The British Association.—The British Association will meet in its fifty-fourth annual session at Montreal, August 27th, under the presidency of Lord Rayleigh. The Vice-Presidents will be the Governor-General of Canada (Lord Lansdowne), Sir John A. Macdonald, Sir Lyon Playfair, Sir Alexander T. Gait, Sir Charles Tupper, Sir Narcisse Dorion, Hon. Dr. Chauveau, Principal J. W. Dawson, Professor Edward Frankland, Dr. W. H. Kingston, and Dr. T. Sterry Hunt. Professor A. W. Williamson will be General Treasurer; Captain Douglas Galton and A. G. Vernon Harcourt, General Secretaries; Professor T. G. Bonney, Secretary; L. E. Dawson, R. A. Ramsay, S. Rivard, S. C. Stevenson, and Thomas White, M.P., Local Secretaries; and Mr. F. Wolferstan Thomas, Local Treasurer. The Presidents of the Sections will be: A, Mathematical and Physical Science, Sir William Thomson; B, Chemical Science, Professor H. E. Roscoe; C, Geology, W. T. Blanford; D, Biology, Professor H. N. Moseley; E, Geography, Colonel Rhodes and P. L. Sclater, Vice-Presidents; F, Economic Science and Statistics, Sir R. Temple; G, Mechanical Science, Sir F. J. Bramwell; H, Anthropology, Professor E. B. Tylor. It is expected that the public lectures will be by Mr. Crookes, Dr. Dallinger, and Professor Ball. The special discussions will be: Friday, August 29th, "The Seat of the Electro-motive Forces in the Voltaic Cell"; and Monday, September 1st, "The Connection of Sun-Spots with Terrestrial Phenomena." Most liberal provisions have been made by the Canadians for the accommodation and entertainment of their guests. The expenses of fifty officers are guaranteed; the Dominion Parliament has appropriated $14,000 toward the expenses of ordinary members; the steamship companies have made considerable reductions of fares; members of the Association are invited to bring their wives and two near relatives with them; the Canadian Pacific Railway offers free excursions to one hundred and fifty members from August 1st till the grand excursion to the Rocky Mountains; and other excursions have been provided for or are contemplated, among which is the excursion to the American Association, which meets in Philadelphia, September 3d.

Death of Professor Klinkerfues.—Professor C. A. Eggert, of the University of Iowa, has kindly furnished us with the following facts respecting the life and work of Professor F. W. Klinkerfues, of the University of Göttingen, one of the most prominent astronomers in Germany, who died by suicide—provoked, it is supposed, by pecuniary losses and excessive use of intoxicating liquors—on the 28th of January last: Professor Klinkerfues was born at Hofgeismar in 1827, and very early manifested a decided taste for astronomical studies. He became a pupil of Gauss, who recognized his very remarkable mathematical talents. Some of his earlier efforts were afterward incorporated, with but little change, in his "Theoretical Astronomy," a work of decided merit. Two of them deserve special mention: one, a new method of calculating the course of a comet from one incomplete and two complete observations; and the other, for the computation of the orbits of double stars. His hypothetical method for the determination of the distance of certain fixed stars belonging to the same system was applied with a satisfactory result to Sirius. Other of his hypothetical combinations were bold and successful in a high degree. Thus, he predicted a close relation between the meteoric shower of November 27, 1872, from the constellations Perseus and Andromeda, and Biela's comet, and that the comet would be found in the opposite quarter of the sky. He telegraphed to the director of the observatory in Madras: "Biela's comet has touched the earth. Look for it in Centaur, near the star ϑ." The comet was found at the spot indicated. Professor Klinkerfues was the discoverer of comets III, 1853; III, IV, 1854; III, 1857; V, 1857, and II, 1863. He was best known in Germany for his predictions of the weather, which he based on the hygrometric indications of moisture in the air. Their fault was, that they depended on the indications at the surface, while the weather goes by the proportion of moisture in the upper strata of the atmosphere, which may be very different. His instrument, known as the Klinkerfues hygrometer, met with considerable success for a time, but was ultimately found to be of little practical value, and is not much used now. Although Professor Klinkerfues was no more successful in other points as a weather-prophet, he has enriched meteorology with observations and facts of some importance; and it would be unjust to classify him with the noisy charlatans whom our newspapers hoist into temporary fame. Notwithstanding his mistakes, the death of such a man is a loss to science. Supplemented by careful observations, his hypotheses on astronomical matters often approached mathematical certainty, and it is not easy to say how much he might yet have accomplished but for the abrupt and melancholy closing of his career.

Facts about British Stature.—The Anthropometric Committee of the British Association, after several years of labor, made its final report at the recent meeting of that body. The committee was appointed for the purpose of "collecting observations in the systematic examination of the height, weight, and other physical characters of the inhabitants of the British Isles," and, in performing its work, took all sorts of measurements of people of all classes, of all ages, and of both sexes, living in all parts of Great Britain, and, to a small extent, of persons living in Ireland. The measurements or observations covered twelve points by which man is externally distinguished from man, and were made upon thousands of people. We notice a few of the more striking results: In average height, the Scotch stand first (68·61 inches), the Irish second, the English third, and the Welsh fourth, while in weight, the Scotch still leading with 165·3 pounds, the Welsh are second, the English third, and the Irish fourth. In the light of these two results, the London "Times" observes that the Scot will look upon the discovery made by the committee "as simply giving the hall-mark of science to his own instinctive conviction that he is a much better man in all respects than the 'fausse southron.'" As between the sexes in England, the average stature of adult males is 67·36 inches, and that of adult females 62·65 inches, while the average Englishman weighs 155 pounds, and the Englishwoman 122·8 pounds. In strength, the Englishman can draw a bow with a power of 77 12 pounds, while the woman brings to bear a force 35 pounds less, or a little more than half as much. In complexion, the lighter shades rule over the country as a whole, but a large percentage of dark complexions stretch in a band across the center of England and Wales. The inhabitants of the more elevated districts appear to possess a greater stature than those of the alluvial plains, and those of the northern and colder districts than those of the southern and warmer parts of the island; those of the northeastern and drier regions are taller than those of southwestern and damper climates. A comparison with American army statistics does not show that the Anglo-Saxon race reaches a higher stature here than in England, as some have claimed, but that a close correspondence prevails between the two groups. Compared with other nationalities in stature, except as to a few extraordinarily tall Polynesians, the English professional class head the list, and the Anglo-Saxon race takes the chief place among civilized communities, though it might stand second to the Scandinavian countries if a fair sample of their population could be obtained. Other general facts deduced from the examinations, as true in the British Isles at least, are that an open-air country life is more favorable to height and weight than a sedentary town life; that favorable hygienic and sanitary conditions have a marked influence on growth and weight; that lunatics show a deficiency of weight and stature, and criminals a greater one, indicating a lack of physical as well as mental stamina in both these classes; that athletes appear a little taller than the general population, and not as heavy; that growth diminishes, as we descend in the social scale, to a difference of five inches between the average stature of the best and most nurtured classes of children of corresponding ages, and of three and a half inches in adults. The population of the manufacturing towns do not appear to be degenerating, but exhibit a slight but uniform increase in stature, and a large increase in weight.

Darwinism in the Talmud.—Dr. B. Placzek, of Brünn, has collected citations from the Talmud to show that the old Jewish writers were keen observers of Nature, and had ideas akin to Darwinism. Joseph Albo, in the fifteenth century, suggested the thought of compensation, or interchange of relations, in an hypothesis that cattle are defective in teeth because so much of the tooth-stuff goes to horn, and that they make up for the resultant deficiency in their powers of mastication by the faculty of chewing the cud. Other writers noticed that the integrity of the comb of the cock had much to do with its masculine potency, and that other birds suffer in spirit and vigor when deprived of their ornamental appendages. A writer in the "Agada" affirmed, in justification of Solomon's selection of the ant as an example of wise industry, that it builds its houses in three stories, and stores its provisions, not in the upper compartment, where they may be rained on, nor in the lower, where they will gather dampness, but in the middle one, the safest place, and that it gathers all it can. The ant is also a fit type of honesty, for it regards the property of its neighbors, and will not rob. Once, it is said, when an ant dropped a grain of corn, a number of other ants came up and smelled of it, but let it lie till the owner came up and took it away. Simon ben Chalafta, "the Experimenter," tells of an experiment worthy of Lubbock. On a very hot day he put a cover over an ant-hill. A sentry ant came out, observed the shadow, and reported upon it to his fellows. They came out to enjoy the coolness of the shade, when it was suddenly taken away, and the insects, irritated by the burning sun, fell upon the scout that had led them into the trap, and killed him. The Agadists make much of the devotion of the individual ant to the welfare of the whole colony as a salient point of formic character. Dr. Placzek suggests that Solomon may have been acquainted with a kind of agricultural ants from his sentence, "Provideth her meat in the summer, and gathereth her food in the harvest," where the former verb may, in analogy with other cases of its use in the Bible, refer to the preparation of the field. Passages are quoted that point to the thought that the difference in mental gifts between men and animals is only quantitative. In one of the books, a limit is set to the scope of scientific investigation thus: "What is too high for thee, seek not to reach; what is too hard for thee, seek not to penetrate; what is incomprehensible to thee, try not to know; what remains hidden from thy mind, strive not to discover. Direct thy thought only to what is attainable, and trouble thyself not about hidden things."

Geological Catastrophes.—The Duke of Argyll, in his address to the Edinburgh Geological Society, on its fiftieth anniversary, took the ground that "nothing can be more unphilosophical than the antithesis and opposition which is set up between what is called the law of continuity and what is called the doctrine of catastrophes. Throughout all Nature, and throughout all those operations of the human intellect which depend on the manipulation of natural forces, we see the two doctrines to be perfectly harmonious—strains and tensions maintaining themselves in absolute silence up to the bending or the breaking-point—pressures pressing with tremendous but noiseless energy up to the bursting point—and then moments of rapid and sometimes of instantaneous change. If it is irrational to quote the continuity of Nature as affording any, even the least, presumption against sudden and great effects, it is still more irrational to quote it as irreconcilable with effects which, though catastrophes to us, whose scales of measurement are often the scales of pygmies, are in reality nothing but movements of infinitesimal smallness in the scale of Nature. I had occasion the other day, in delivering a popular lecture in Glasgow, to exhibit a section of the globe drawn to the scale of one tenth of an inch to a mile. On that scale, which I have taken from my friend Mr. James Nasmyth, the globe is represented by a circle sixty-four feet in diameter, and I was able to show that on that portion of the curve which represents one eighth of the circumference, the elevation of the highest mountain in Europe, Mont Blanc, was wholly invisible to the spectators who were half-way down the hall, and could barely be seen even by those who were close at hand. The truth is, that, when we come to realize the almost infinitesimal smallness of the irregularities of the earth's surface as compared with its circumference—the whole range from the highest height to the deepest deep being somewhat less than sixty thousand feet—the wonder comes to be that if subterranean forces are at work at all in modifying, from time to time, the perfect smoothness and sphericity of the surface, not that their work should be so great, but, on the contrary, that it should be so very small."

Causes of Typhoid Fever.—In a paper published by the Iowa State Board of Health on the nature, causes, and prevention of the typhoid fever of America, Dr. R. J. Farquharson. Secretary of the Board, emphasizes the distinction between typhus and typhoid, an important point of which is, he believes, that typhoid is not contagious. A number of reports, American and foreign, seem to concur in fixing the origin of the disease in some condition of the ground or water, and indicate that it may be produced by foul water, by foul air, or by emanations from the earth, occurring most frequently in the autumn and during seasons of drought. It has sometimes been traced with every evidence of probability to decayed wood, and this indicates that vegetable decay is one of the prime sources of its origin—a view which the fact that it has been produced by the drying of ponds does not contradict, but rather supports. A direct connection is traced, in the United States, between the increase of summer temperature and this disease. The curves of normal temperature, of typhoid fever, and of malarial fevers are almost exactly parallel, except that the culmination of the fever curve, in September for Iowa, October for the Eastern States, is behind that of the temperature curve, which occurs in July. A general parallelism, but without the uniformity of the culminating point of fever, has, with the exception of one spot (Munich), been observed in Europe. Since the disease is not contagious, the minute directions for isolation, disinfection, destruction of clothing, etc., so eminently proper in really contagious diseases, are useless in typhoid fever. In our present knowledge of the causes of the disease, but little can be done, and that only in a general way, to prevent it. The principal points are to see that the drinking-water is pure, that the house is well ventilated and not built over a marshy spot, that slops are removed far enough away, and that the drains are kept clean and washed and are occasionally disinfected with copperas; and, when sickness occurs, the patient should be given quiet and plenty of fresh air.

The Weather and Neuralgia.—The case of Captain R. Catlin, United States Army, as reported by Dr. S. Weir Mitchell, affords a curious illustration of a relation between neuralgic pains and meteorological condition. Captain Catlin had his foot crushed by a round shot in August, 1864. His leg was amputated below the knee. Pain was felt early as if in the lost foot, and became severe within nine months, while in other respects Captain Catlin is and has been in perfect health. Since 1871, the captain has kept a regular record of the hours of pain he suffered each year and each month. The maximum of pain was attained in 1874 and 1875. During 1876 the amount of pain fell off 100 hours (from 1,892 to 1,790), with a decrease of mean annual pressure and a corresponding increase of temperature. For 1877, pain and pressure remained constant and parallel, with some increase in temperature. In 1878 the pain decreased 200 hours, while an equally remarkable fall was shown in the barometric curve. The law of relationship of low pressure and high temperature to the amount of pain and the number of attacks of pain and the number of storms becomes more apparent in considering the quarterly and monthly distribution of pain and storm. "The winter months hold the advantage as pain-producers," while in quarterly amounts the first quarter, beginning with the winter solstice, leads; the fourth quarter, ending with the winter solstice, follows; and the second, or spring quarter, is next. In months, March holds the lead, and is closely pressed by January, after which follow November, December, May, February, April, August, October, September, July, and June. The average duration of each attack of pain during eight years was 18·97 hours. The duration also bears a relation to the amount of pain and the number of storms, and is greatest in February. To determine the average distance of the storm-center at the beginning of the pain-attack, sixty well-defined storms through ten consecutive months were taken. The average distance was six hundred and eighty miles, the particular distances ranging from two hundred to twelve hundred miles. It has been observed that eating a meal, when the pain is on, intensifies it, and it is believed that it often hastens the attack. During seven years (1875 to 1882) nine neuralgic attacks of great and unusual power were observed, and a coincidence was traced between them and storms of extraordinary intensity. The best regimen for this neuralgic subject has been found to consist in physical exercise, nutritious food, and light, agreeable occupation.

Dr. Michael Foster on School Examinations.—Dr. Michael Foster, in a recent address before a pharmaceutical school in London, gave a vigorous expression to his views respecting examinations. The passing of an examination was regarded as a mark, stamp, or certificate, of what? He ventured to think that success in this sphere of action merely indicated that the prize-man had the ability and skill to get on in an examination. No doubt a stupid and idle man could not get first places in examinations, and so the industrious and clever were picked out by the process. But it was certainly not the case that those who failed to get the highest honors in examinations went to the wall in after-life. On the contrary, he was sorry to say that he knew some who had succeeded to the fullest extent during the examinational period of their life, yet did not maintain their prestige as time rolled on. And not a few men who were signal failures at examinations have proved of enormous value in after-years. To some a vast amount of evil was wrought from the fact that no proper knowledge had been acquired to pass the standard. He advocated a plan of examination which is partly carried out at the School of Science, South Kensington. That was, to study and be examined on each subject separately, and by the same persons who had acted as teachers.

The Future of Physiological Experiment.—Professor Tyndall founds a new argument in favor of the practice of experimental physiology in the peculiar properties of infectious diseases, and their probable germ origin. One of the most extraordinary and unaccountable experiences in medicine has been the immunity secured by a single attack of a communicable disease against future attacks of the same malady. Small-pox, typhoid, and scarlatina, have been found, for example, as a general rule, to occur only once in the lifetime of the individual, the successful passage through the disorder seeming to render the body invulnerable against future attacks. Professor Tyndall had some time ago suggested to a friend that the phenomenon could be explained under the germ theory by supposing the soil, or the system, to be exhausted by the first parasitic crop, of some ingredient necessary to the growth and propagation of the parasite. Some important essays on the subject have been recently published in the "Revue Scientifique" by M. Bouley, who draws attention to the results obtained by M. Raulin in the cultivation of the microscopic plant Apergillus niger. The omission of potash from M. Raulin's liquid suffices to make the produce fall to one twenty-fifth of the amount collected when potash is present. The addition of an infinitesimal amount of a substance inimical to the life of a plant is attended with still more striking results. For example, one part in 1,600,000 of nitrate of silver added to the liquid entirely stops the growth of the plant. Now, supposing the aspergillus to be a human parasite—a living contagium—capable of self-multiplication in the human blood, and of so altering the constitution of that liquid as to produce death; then, the introduction into the blood of a man weighing sixty kilogrammes, of five milligrammes of nitrate of silver would insure, if not the total effacement of this contagium, at all events the neutralization of its power to destroy life. An index-finger here points out to us the direction which physiological experiment is likely to take in the future. In anticipation of the assault of infectious organisms, the experimenter will try to introduce into the body substances which, small in amount, shall so affect the blood and tissues as to render them unfit for the development of the contagium. And, subsequent to the assault of the parasite, he will seek to introduce substances which shall effectually stop its multiplication. Dr. Polli, of Milan, has already obtained results that promise well with alkaline sulphides in certain fevers and small-pox, and Crudelli obtained similar results with arsenic against the malaria of the Roman Campagna. To enable us to administer these remedies safely and with some assurances of success, experiments must be made of their effects, on different groups of individuals, and these individuals must be animals susceptible to the infection and to the counteracting application. "I appeal," says Professor Tyndall, "not to the partisans of either side, but to the common sense of England, whether, in the interests of humanity, the proposed experiment is not a legitimate one."

Effect of School-Work on the Brain.—A question was recently asked Mr. Mundella, in the British House of Commons, as to the effect of the English educational system on the health of children and teachers. He replied in substance, availing himself of the reports of the Lunacy Commissioners, that the effect of education had been, even in the midst of a rapidly-increasing population, to diminish the absolute number of children admitted to asylums. So, of the group described as teachers, schoolmasters, schoolmistresses, governesses, professors, and lecturers, the proportion admitted to asylums was less than that of any other profession. This statement should dispose of much of what is said about the ordinary routine of school occupation leading to mental disease. While pupils who are stimulated or pressed, by cramming, to over-exertion may suffer injury, a lively exercise of the mental faculties on some varieties of subjects, which is the most that the majority of school-children attain, is more likely to be promotive of vigor. The fact that insanity prevails most among agricultural laborers in the rural counties, where the standard of education is lowest, and mental vacancy is least interrupted, tends to show that absolute blankness of mind, like the non-use of a physical faculty, promotes disease. So with teachers: while the demands on their brains are constant and call for vigorous exercise, they are, as a rule, seldom of a kind to involve overwhelming pressure, or so irregular as to admit of intervals when the mind is wholly unemployed and liable to morbid reaction.

Poisons developed in the Body.—On this subject Dr. Benjamin W. Richardson says: "In my reports to the British Association for the Advancement of Science, I have pointed out that the substance amylene, an organic product which can be easily constructed in vital chemical changes, produces phenomena identical with those of somnambulism and with some of the phenomena of hysteria. I have pointed out, in the same reports, that another organic product, called mercaptan (sulphur-alcohol), causes, when inhaled, symptoms of profoundest melancholy, and that, in the process of being eliminated by the breath, it gives to the breath an odor which is identical with the odor evolved in the breaths of many patients who are suffering from the disease called melancholia. From these observations I have ventured to suggest that various forms of mental affection and of nervous affection depend for their development on the presence in the body of organic chemical compounds, formed and distilled through an unnatural chemical process carried on in the body itself. I have endeavored to develop this subject somewhat further by my researches on the action of lactic acid on animal bodies. I have shown by experiment that this acid, diffused through the body by the blood, acts as a direct irritant upon the lining membrane of the heart, the endocardium, and all the fibro-serous membranes of the body, so that a synthesis of heart-disease and rheumatism can be established by its means. Lactic acid is the most copious product thrown out in the disease called rheumatic fever, and, as many of the phenomena resulting from that disease take the same form and character as those producible by lactic acid, I infer from the best evidence attainable that this acid, the product of a fermentative change going on in the body during acute rheumatism, is the cause of the secondary structural affections which so frequently follow acute rheumatism. It has been for some time past observed by several able physicians that persons who are suffering from the affection known as diabetes give off a peculiar odor from their breath—an odor which to some is like that of vinegar, to others of sour beer, to others of a mixture of ether and chloroform, to others of acetic ether. I should compare it myself to the odor of grains as it is detected in a brewery. When this odor is observed in the breath of diabetic patients, it frequently happens that they become sleepy, cold, and unconscious, with the results of coma and death. At one time it was supposed that these phenomena were uræmic, and were due to the presence of urea in the blood; but the absence of convulsion and of some other symptoms destroys this hypothesis, or at all events shakes it. It is now believed that the symptoms owe their origin to the decomposition of the diabetic sugar which is in the body, and to the production from that decomposition of a volatile ethereal fluid called acetone a fluid which has been discovered in the blood and secretions of these affected persons, who are said therefore to be suffering from the disease 'acetonæmia.' From the action of acetone upon animal bodies I infer that the theory of acetonæmia is founded on good evidence." Dr. Richardson mentions also the secondary absorption of poisonous matter from wounds, and from the abraded and ulcerating surfaces produced in diphtheria, malignant scarlet fever, etc., and concludes by saying: "Such observations as have been noticed under this short head lead to a study of another new point, namely, the possibility of the formation of organic alkaloids in the body during some conditions of disease. Scientific discovery has not, however, advanced so far as to enable me at this moment to do more than allude to one of the newest and most important studies in modern medical research."

Mechanism of Plant-Contraction.—Dr. J. Burdon-Sanderson, in a lecture before the Royal Institution of Great Britain, performed an experimental demonstration of the causes and phenomena of the excitability of plants. The number of plants which exhibit what is often called irritability is very considerable, but the illustrations of the lecture were drawn chiefly from typical specimens of only a few of the most familiar kinds, such as mimosa, dionea, and two or three others. The mimosa presents nearly the same appearance when asleep as when excited, but is then liable to a further change, by the operation of which it sinks to a still lower position and becomes limp. The excitatory effect is dependent on a vital change in the protoplasm of the cells, which may be observed when the plant is asleep as well as when it is awake. The cells of the plant, which unexcited are distended or charged with liquid, undergo on excitation a sudden diminution of tension or of expansion by the discharge of the water contained in them, which finds its way first into the intercellular air-spaces, and then out of the motor organ altogether. The discharge is due to a sudden loss of its water-absorbing power by the protoplasm of the cell, whereby the external cell-sac, whose elastic tendency to contract is kept in check only by the constantly distending action of the protoplasm presses upon it with force enough to squeeze out the cell-contents. This action being participated in by all the individual cells, the leaf-stalk, or whatever organ it may be that droops, necessarily becomes limp and falls. The motion of the leaf is, however "the result of the action of many hundred independent cells, all of which may act together, but may not. In either case they take a great deal longer to think about it; for during a period after excitation, which amounts at ordinary summer temperature to about a second, the leaf remains absolutely motionless." During this interval an electrical disturbance takes place in the plant, the character and operation of which were neatly shown by the aid of some extremely delicate apparatus. Obvious and well-marked differences were pointed out between the mechanism of plant motion and that of animal motion; but the differences are not essential, for they depend not on difference of quality between the fundamental chemical processes of plant and animal protoplasm, but merely on differences of rate or intensity. "Both in the plant and in the animal, work springs out of the chemical transformation of material, but in the plant the process is relatively so slow that it must necessarily store up energy, not in the form of chemical compounds capable of producing work by their disintegration, but in the mechanical tension of elastic membranes. The plant-cell uses its material continually in tightening springs which it has the power of letting off at any required moment by virtue of that wonderful property of excitability which we have been studying. Animal contractile protoplasm, and particularly that of muscle, does work only when required, and, in doing so, uses its material directly."

Origin of Winding River-Beds.—Major Stevanovics, a Hungarian officer, has published an essay on the laws by which the "wash" and meandering of rivers are regulated. Based on studies of the Theiss and the Danube, the principles he elucidates are illustrated in the windings of rivers the world over, with such variations only as differences in situations and exposures might occasion. The deviations which rivers are constantly making in their course are, it appears, determined by fixed laws, which engineers should be competent to find out and regard. To understand them more fully, we may imagine our river straight, evenly broad and deep, with no marked channel, and without tributaries. The formation of a channel begins as soon as a bit of the earthy constituents contained in the water is deposited on the ground under it. This causes an unequal distribution of the weight of the water, and a stronger inclination toward one or the other edge. The deposit slowly grows, and a sand-bar is formed, which presses the current over toward one side and gives it an angular direction. This causes it to strike with more force against one of the shores, and to wash it, eat it away, or undermine it, equally whether it be of earth or stone. Should there be a tributary coming in from the opposite side of the sand-bar, that will occasion the formation of a second bar, and this will cause the current to make another turn and render its course serpentine. In this way a system of bars is formed, that are represented in the course of time by dry alluvial deposits, from which the river has been constantly pushed to one side. Many of the peculiarities of African and other rivers may be explained by reference to these principles. The great bends of the Congo and the Niger may be accounted for by supposing that the hills that run parallel to their courses were weathered most on the side most exposed to the sun so as to cause a constant growth of the bars on the north side and a gradual pushing of the stream toward the equator. In Hungary, the courses of the streams are modified by the operation of another force, that of the equinoctial winds called the koschava which blow in the spring and fall for days at a time from the southeast. The waves are driven by the wind, especially at the time of high water in the spring, with more force against the western bank, and make longitudinal excavations in it at the level of the water. After the retiring of the flood, the overhanging bank gives way and slides into the river, with a noise which is quite familiar to the people, and well understood by them. These excavations, extended and deepened by subsequent operations of the same kind, result in the formation of large bends; and the river has become very serpentine, with numerous narrow peninsulas jutting out at right angles to its current. Finally, the peninsulas are cut through and formed into islands, to become in time, as has been the case in some instances, by the operation of continued changes of the stream, a part of the other bank. Observations of this kind have been made in the Danube, and the phenomena accounted for by them are familiar on other rivers. Changes by another kind of process are caused by the fall equinoctial winds, which, instead of finding high water in their way, take up the dry sand and deposit it in drifts where they will exercise a modifying influence on the course of the river. The changes that have taken place in the Amou-Darya of Turkistan, under which its course has been diverted from the Caspian Sea to the Sea of Aral, are probably effects of an agency of this kind.

Russian Scientific Societies.—Science is promoted in Russia by several societies that are very active in their respective fields of investigations, and which have earned for their country a respectable place among the nations where knowledge is diligently and intelligently cultivated. The Kiev Society of Naturalists was formed in 1869, and is supported by a considerable membership. Its chief aim has been the exploration of the natural history of the neighboring provinces. Its published "Transactions" bear evidence of good work done in geology, zoölogy, botany, and kindred sciences. Since 1873 it has undertaken the yearly publication of a systematic catalogue of papers in mathematics, pure and applied, natural science, and medicine, printed in the numerous scientific publications of the empire. The East Siberian branch of the Russian Geographical Society, having already contributed largely to the purely geographical exploration of the unknown parts of Siberia and the adjacent countries, has now become engaged upon a more thorough scientific exploration of Siberia itself. Among its later publications is an excellent geological map of the coasts of Lake Baikal. The Siberian branch of the Geographical Society has within the last few years taken a lively interest in anthropology and archæology, and has been the means of making known many valuable discoveries in these branches. It has also paid much attention to the meteorology of Siberia, has taken regular observations at meteorological stations, and has collected materials for ascertaining the dates of the freezing and breaking up of the ice in the rivers of the country.